The Women's Health Initiative represents a large population-based sample of 161,000 postmenopausal US women. These women have been well-characterized in terms of demographics, diverse exposures, quality of life assessments and incidence of chronic diseases, including over 20,000 incident invasive cancers over a mean 12 years of follow-up. A biorepository maintains >5 million vials of serum, plasma and DNA, and over 93,000 women continue in active follow-up. WHI investigators seek to enhance opportunities for cancer survivorship studies, particularly those that recognize the import of molecular heterogeneity of tumors, by addressing two key limitations in the existing program. Specifically, we propose to; 1) collect information on cancer treatment, clinical outcomes (recurrence) and patient reported outcomes in women diagnosed with selected cancers (breast, colorectal, endometrial, lung, and ovarian cancers, lymphoma, leukemia, and melanoma, projected n=21,882) during WHI participation using Medicare linkages or direct medical record abstraction; and 2) collect paraffin-embedded tumor tissue from selected cancers (colorectal and ovarian cancers, melanoma, lymphoma, and breast and lung cancer subtypes, projected n=5,900). We will collect treatment and outcome data via linkage to Medicare datasets for cost efficiencies, whenever possible, and will pursue and evaluate methods to collect these data through access to other administrative databases. By enhancing the WHI database with cancer treatment and recurrence data, WHI will be a valuable resource to examine the effects of cancer diagnosis and treatment on overall health and quality of life in an aging cohort-one that represents the fastest growing population, bears the great cancer burden but has been under-represented in randomized trials. By supplementing the specimen repository with tumor specimens, the WHI Program will be able to support up-to-date phenotyping of cancers and contribute to our understanding of the molecular basis of cancer, its treatment and survival. We want to begin soon to ensure that a large and representative resource can be realized, because tumor tissue and records for cases diagnosed in the early period of the WHI will become increasingly difficult to obtain.